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

Annotations already declare readOnlyHint=true, destructiveHint=false, openWorldHint=true, so the safety profile is covered. The description adds genuine value by decoding the a–f state codes and saying totals and items are included in the response. It says nothing about pagination or quota behavior, both of which are only in the schema.

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 compact sentence plus a short tag; the state-code enumeration earns its space. The 'estimate.get' suffix is the one wasteful fragment.

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 plain list tool with a read-only annotation set and no output schema, the description covers output content but leaves optional-filter usage and pagination behavior unexplained, which matters given seven optional parameters and zero required ones.

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 57%, and the description mentions no parameters at all. Three filters (customer_id, estimate_id, estimate_number) have no description in either the schema or the tool description, so the caller gets no semantic guidance on how those filters combine or whether they are exact-match.

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?

States a specific verb and resource ('List estimates (quotes)') and clarifies the domain term, which distinguishes it from fastbill_create_estimate and the invoice-listing siblings. It also names the fields returned (state, totals, items). The trailing 'estimate.get' is an opaque internal reference that adds no clarity.

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?

There is no indication of when to use this versus fastbill_get_invoice-style lookups or the create/update siblings, and no mention of the filtering options (dates, customer, estimate id/number) that would guide a caller. Usage is only implied by the verb 'List'.

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