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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds that the lookup is scoped to a fixed, closed set of seven tools, which is consistent with and mildly reinforces the annotations, but it says nothing about response shape, errors for unknown ids, or rate limits.

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?

Two short sentences, front-loaded with the purpose and followed by the only constraint that matters. No filler.

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 single-parameter read tool with annotations covering safety, the description is adequate to invoke the tool correctly, and the enum compensation is the critical piece. However, with no output schema, the agent gets no sense of what 'plans and limits' actually returns.

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 0% and the schema declares tool_id as a bare string with no enum, so the description carries the full burden — and it does, enumerating all seven valid values. It does not state case sensitivity or format expectations, keeping it just below a 5.

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 resource ('plans and limits') and scope ('for one tool'), which implicitly contrasts with the sibling list_plans. It never names the sibling or explicitly says how it differs, so it stops short of a 5.

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 phrase 'for one tool' implies the use case (single-tool lookup vs. a broad listing), but there is no explicit when-to-use, no when-not-to-use, and none of the three siblings (get_recent_changes, list_plans, recommend_plan) is named as an alternative. Usage is only inferable from scope.

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