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

Annotations already declare readOnlyHint=true, so the safe-read behavior is covered. The description adds some value beyond the annotations by revealing the API endpoint and the return shape ({ list }), but it does not disclose pagination, limits, or any ordering/filtering behavior, which would be genuinely useful context for a list endpoint.

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 terse sentence that front-loads the core purpose and appends the endpoint and return format, with no filler. Every clause carries information an agent can act on.

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?

With a 100%-covered schema, no required parameters, and annotations supplying the read-only safety profile, the description covers the essential contract: what it lists, the endpoint, and the response shape. It is adequately complete for a simple collection endpoint, missing only optional niceties like pagination details.

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%, so all four parameters (entity_id, customer_id, all_versions, include_archived) are already fully documented by the schema. The description adds no parameter-specific meaning beyond the { list } return note, which fits the baseline-3 expectation for high schema coverage.

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 ('List') and a clear resource ('plans (products)') scoped to the current environment, and names the underlying API endpoint (POST /v1/plans.list). This clearly differentiates it from siblings like get_plan (singular retrieval) and attach_plan (mutation), so an agent can tell it apart without opening the schema.

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 description says 'List all plans,' which implicitly positions this as the batch/collection operation distinct from get_plan and attach_plan among the siblings. However, it never explicitly states when to prefer this over the alternatives or when not to use it, so the routing guidance is implied rather than stated.

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