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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds value beyond that by disclosing that only the current version's body is returned and that the response bundles the JSON Schema body with the schema record. No contradiction with annotations exists.

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

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

A single front-loaded sentence carries the action, the identification method, the response content, and the purpose with zero filler. Every clause earns its place, and the key scoping detail ('current version') appears before the purpose clause.

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

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

For a simple 2-parameter read-only tool with an output schema, the description covers how to identify the resource, what will be returned, and why the agent would want it. Nothing an agent needs for normal invocation is missing; the precedence if both slug and schema_id are provided is a minor edge not worth penalizing here.

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

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

Schema description coverage is 100%, with both slug and schema_id already documented including their either/or intent. The description's 'by slug or id' only restates what the schema says, so it adds no new semantic meaning beyond the structured definitions — baseline 3 applies.

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

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

The description states a specific verb and resource — 'Get a single schema' — and adds distinguishing qualifiers: lookup by slug or id, and inclusion of the current version's JSON Schema body. The 'single' qualifier separates it from list_schemas, and 'current version' separates it from version-specific or definition-schema getters among the siblings.

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

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

The clause 'use it to author a datafile that conforms' gives a clear, actionable context for when to invoke this tool, implicitly routing an agent to fetch the schema before creating or updating a datafile. It does not go so far as to name alternatives or state exclusion cases, so it stops short of a 5.

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