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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds a behavior the annotations cannot express: the call does not consume the daily quota, which is exactly the kind of side-effect context an agent needs. It stops short of describing response shape or whether quota resets are timezone-based, so it is not a 5.

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, zero filler. The output content is front-loaded and the quota-cost note follows as a compact second sentence. Nothing could be removed without losing meaning.

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?

A zero-parameter read tool with a clear output statement ('plan ... and how many calls remain today on each tool') needs nothing more; there is no output schema, but the description enumerates the returned fields. Combined with annotations covering the safety profile, an agent has everything needed to call it correctly.

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?

The tool takes zero parameters, so there is nothing for the description to disambiguate and the baseline of 4 applies. Schema coverage is 100% and the empty object schema is self-explanatory.

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 names a specific verb ('Show') and two concrete resources: the caller's plan tier (Free or Pro) and the per-tool remaining daily call counts. No sibling tool reports account/plan/quota status, so it is trivially distinguishable from the audit/lint/report family.

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 sentence 'Does not use up a daily call' implicitly tells the agent this is a free/cheap call it can make liberally, which is genuine usage guidance. However, it never states when to call it (e.g., before running expensive audits to confirm quota) or any exclusion — the timing guidance is left entirely to inference.

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