repo_summary

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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds one useful behavioral constraint, the ~600 token output budget, which helps an agent plan context usage, but says nothing about pagination, caching, or what "index freshness" means operationally.

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?

Extremely tight, front-loaded, and every clause carries information: the content list, the priority signal, and the token budget. Not wasteful, though the telegraphic style borders on under-specification.

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 no output schema, the description correctly summarizes what is returned and bounds the response size. For a single-optional-parameter read tool with readOnlyHint annotation, this is close to sufficient; only the limit parameter and freshness semantics remain unexplained.

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?

There is one optional integer parameter (limit, default 10) with 0% schema description coverage, and the description never mentions it. The parameter is nearly self-explanatory by name and has a default, so the gap is minor, but the description does not compensate for the missing schema documentation.

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 the resource (repo) and enumerates the specific content returned: languages, size, packages by lines, index freshness. This differentiates it from symbol-level siblings like get_symbol and search_symbols, though the verb is implicit (it returns an overview rather than performing an action).

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?

"Start here" is a genuine usage signal, orienting the agent to call this before drilling into siblings. However, it offers no explicit when-not guidance and does not name any alternative for follow-up questions, leaving routing to inference.

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