gryzzly-mcp

create_discount

Adds a discount to a single project or task, with a name and amount. Verify existing discounts first to prevent duplicates.

Instructions

Grant a discount on exactly one project or one task, named or identified, with a name and an amount taken off its budget. Use it to add a discount; use update_discount to change one. Each call creates a new record, so check list_discounts first to avoid granting it twice. Passing both a project and a task, or neither, is refused before any request. Requires Gryzzly's budget offer.

Input Schema

TableJSON Schema

Name	Required	Description
`name`	Yes	The discount's name.
`task`	No	The task it applies to, by name or id. One of project or task.
`amount`	No	How much is taken off.
`project`	No	The project it applies to, by name, code or id. One of project or task.

Output Schema

TableJSON Schema

Name	Required	Description
`id`	Yes	The discount's identifier.
`name`	No	The discount's name.
`amount`	No	How much is taken off.
`task_id`	No	The task it applies to.
`created_at`	No	When the discount was created.
`project_id`	No	The project it applies to.
`updated_at`	No	When the discount was last updated.

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Oct 20, 2026

TDQS

A4.6/5.0

Behavior5/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare non-read-only, non-idempotent, non-destructive, open-world behavior, and the description goes further by disclosing the validation rule (both project and task, or neither, is refused before any request is sent) and an entitlement prerequisite (Gryzzly's budget offer). The non-idempotency consequence is also made actionable via the list_discounts warning.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The scope constraint and the create-vs-update distinction are front-loaded, and every sentence carries either scope, routing, or a prerequisite. Slightly long across four sentences, but there is no filler or restated name/title.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a mutation tool with an output schema available, the description need not explain return values, and it covers what matters: scope, sibling routing, duplicate-avoidance workflow, pre-request validation, and the budget-offer prerequisite. Nothing an agent needs to call it correctly is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so name, project, task, and amount are already documented, including the 'one of project or task' note. The description restates the one-of constraint and adds a small amount of enforcement detail (refused before any request), but supplies no new format, unit, or identifier syntax beyond the schema. Baseline 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb (grant) and resource (discount) plus the exact cardinality/scope: exactly one project OR one task, named or identified, with a name and an amount off budget. That level of precision separates it cleanly from update_discount, get_discount, and delete_discount without opening any schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines5/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly routes creation to this tool and modification to update_discount, and adds a concrete pre-call workflow: check list_discounts first because each call creates a new record. This is when-to-use, when-to-use-something-else, and a de-duplication guard in three sentences.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.