List known repositories

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

With annotations already declaring readOnlyHint and openWorldHint=false, the description adds substantial operational context: freshness semantics (ttl/always/manual), the fact that manual entries never self-refresh, that unsupported clone_strategy makes a project refuse to be read until re-cloned, and that synced_at may be 'unknown'. This is behavior an agent cannot infer from the 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 output-column enumeration is dense but front-loaded with purpose, and each column row earns its place given there is no output schema. Slightly long, but no clearly redundant sentences.

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?

There is no output schema, so the description compensates by documenting the full row layout (path, source, freshness, ttl, clone_strategy, present, local_path, synced_at). Combined with the freshness and re-clone caveats, it is complete enough for an agent to call and interpret the result correctly.

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 the schema carries no semantic burden; the baseline for a 0-param tool is 4. The description instead spends its budget on return-shape semantics, which is appropriate but not a parameter concern.

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+resource ('List the repositories this server knows about') and immediately scopes it with the freshness policy and sync state, which no sibling does. It also contrasts with add_repo and sync_repo, letting an agent place it among the siblings without opening a schema.

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?

Gives clear routing context: add_repo registers a mirror-backed project before first use or points at an existing clone, and freshness=manual cases should be refreshed via sync_repo. There is no explicit 'use list_repos when X vs Y' statement, so it stops short of full when/when-not guidance.

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