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

The description discloses that points are recorded snapshots rather than implied values, describes the exact output structure (composite + agent readiness per date, summary metrics), and includes pricing. This goes beyond the readOnlyHint annotation, though auth requirements and rate limits are not covered.

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?

The description is moderately long but front-loaded with the core purpose and each sentence adds meaning. The pricing and plan details are useful, though the 'UNDERSTANDING' prefix and emphatic 'REAL' add minor noise. Overall efficient.

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?

Given no output schema, the description does a good job explaining the returned data: per-build composite and agent readiness, plus summary statistics like first/last, net change, direction, and largest jump. It doesn't mention data range or pagination, but for a single-provider series this is likely sufficient.

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 description implies slug identifies the provider but never explicitly defines it or explains how to obtain it. The context parameter is well-described in the schema, but the required slug has no schema description and the description only partially compensates for this gap.

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 clearly states the tool returns a provider's score time series with one point per scored build and a movement summary. It emphasizes 'provider' and 'time series', which distinguishes it from cohort-level or current-rating tools, though it does not name sibling tools explicitly.

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 implies usage when historical rating trends for a single provider are needed, but it does not explicitly state when to prefer this over tools like get_provider_rating or cohort_history, nor does it mention when-not-to-use or alternatives.

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