list_shares

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

readOnlyHint=true already establishes this is a safe read, so the description's real contribution is the filtering semantics: only ACTIVE shares, only those OWNED by this account, and only within the credential directory. That tells the agent what will not appear in results, which is the main behavioral risk here. It stops short of covering ordering, pagination, or how expired/revoked shares are treated.

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?

One sentence, front-loaded with the verb and resource, with each qualifier carrying distinct meaning (active status, ownership, directory boundary). Nothing is repeated from the name or title and nothing is padding.

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 low-complexity, zero-parameter read tool with an output schema, so the description does not need to explain return values. The scope qualifiers cover the important ambiguity, though it does not clarify whether shares owned by others but visible to this account are excluded, nor whether only unexpired shares qualify as "active".

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 baseline is 4 and there is no parameter meaning for the description to supply. Its scope phrases instead describe implicit filters baked into the call, which is a mild bonus rather than a requirement.

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 a specific verb and resource ("List active shares") and narrows scope with two qualifiers: owned by this account and within the credential directory. This is enough to separate it from list_links and list_file_requests without opening a schema, though it never names those siblings to sharpen the contrast.

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?

Usage is only implied: an agent can infer this is the read path where create_share and revoke_share are the write paths. There is no explicit when-to-use or when-not-to-use statement, and no mention of how to enumerate links versus shares if the agent is unsure which collection a resource lives in.

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