Save the repo architecture digest

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

Annotations already indicate this is a write operation (readOnlyHint=false), idempotent, and not destructive. The description adds key behavioral detail by stating 'Overwrites the previous one,' which is important for user expectations. It also explains the mechanism of 'covers' for future change notification. There is 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 concise sentences, front-loaded with the primary purpose, and each clause earns its place. It avoids fluff and includes a clear directive ('Save the why and the shape').

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?

This is a simple save tool with no output schema and only two well-documented parameters. The description, combined with annotations and schema, fully conveys the tool's behavior, including overwrite semantics and the role of covers. It does not discuss error handling or return values, but that is not critical for this straightforward tool.

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 description coverage is 100%, so the baseline is 3. The schema already describes 'text' and 'covers' well, and the tool description reinforces this with guidance like 'the why and the shape, not a symbol list' and 'omit = whole repo' for covers, but it does not add substantial new meaning beyond the schema.

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 action ('Store') and the specific resource ('a compact 'how this repo works' cheat-sheet'), and distinguishes it from sibling tools like digest_get (retrieval) and memory_save (general memory). It also clarifies what the digest should contain ('modules, flows, entry points, conventions'), avoiding ambiguity.

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 explains the practical benefit ('future sessions read a page instead of re-exploring') and the role of 'covers' for tracking changed files. It implicitly indicates when to use this tool (to persist architecture knowledge) but does not explicitly contrast it with alternatives like memory_save or index_repo, so it lacks explicit 'when not to use' guidance.

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