get_index_overview

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

The annotations already declare readOnlyHint=true, but the description adds valuable context: counts come from the index and may be stale, and the tool aggregates data from multiple earlier versions. This goes beyond the annotation and helps the agent set expectations about data freshness. No contradiction with annotations.

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 two sentences: the first lists all outputs and the second gives the use case and a caveat. It is front-loaded and every clause earns its place. No redundant or filler content.

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 read-only snapshot tool with a simple 2-parameter schema, the description covers its purpose, returns the fields, the use case, and the data freshness caveat. There is no output schema, so the explicit list of fields is sufficient. The context is complete.

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 coverage is 100%, so the description does not need to elaborate on parameters. It mentions the top_tags/top_roles outputs which relate to top_n, but the schema already documents top_n's behavior (default, minimum, and semantics). The description adds no additional parameter meaning, so a baseline 3 is appropriate.

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 what the tool does: a single-call repo snapshot listing specific aggregations. It also provides a concrete use case ('what is this repo at a glance?') and distinguishes itself by being a composition of earlier aggregations. The verb 'snapshot' plus the enumerated fields makes the purpose unambiguous.

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 explicitly says 'Use for "what is this repo at a glance?"' which is a clear when-to-use statement. It also warns that counts are only as fresh as the last index run, implying not for real-time queries. However, it does not explicitly name alternatives or when-not-to-use, so it falls short of a 5.

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