repo_cache_stats

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

The description asserts 'Read-only, in-memory diagnostics, zero side effects,' but the annotations declare readOnlyHint=false and openWorldHint=true, directly conflicting with that claim. An agent relying on the prose would misjudge the safety profile of this tool. This is a genuine annotation contradiction rather than ordinary missing context.

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?

Well front-loaded and organized with labeled 'When to use', 'When NOT to use', and 'Output' segments; each sentence is short and purposeful. Slight redundancy in piling 'Read-only, in-memory diagnostics, zero side effects' on top of annotations that already cover mutability, and that stacking is what creates the conflict.

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 parameters and no output schema, the description supplies what an agent needs: what the tool reports, the named metrics, and where the sibling tools handle repo searching. The only real gap is that it does not reconcile its read-only framing with the annotation-declared openWorldHint/readOnlyHint values.

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 per the baseline the schema carries no semantics to explain. The description instead names the metric fields it returns (hits, misses, size, max_size, ttl_s), which is extra useful detail even though it is about output rather than input.

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 verb and resource — 'Retrieve runtime diagnostic counters for the tool result cache' — and enumerates the counters (hits, misses, size, max_size, ttl_s). It is clearly distinguishable from siblings like repo_map and repo_search, which it explicitly names as not-this.

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?

Provides explicit 'When to use' (evaluating cache hit rate, debugging server performance) and 'When NOT to use' (searching repository contents or inspecting code structure) with named alternatives (repo_map, repo_search). Nothing is left to inference.

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