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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description adds real value beyond that: it discloses the auth requirement ('Requires your API key') and two concrete negative behaviors (no file download, no share URL returned), preventing a common mistaken expectation. It doesn't cover error behavior for unknown or revoked grants, keeping it from a 5.

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?

Three short sentences, front-loaded with the resource and its returned fields, followed by exclusions and the auth requirement. No redundant restatement of the title and no filler.

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 usefully enumerates the returned fields and states what is deliberately omitted, which is exactly what an agent needs for a read tool. Minor gap: no mention of behavior when the grant is revoked/expired or not found.

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%, including the api_key header-preference guidance and grant_id provenance, so the schema carries parameter semantics. The description only reinforces the api_key requirement and clarifies that token_prefix is a prefix rather than the secret; baseline 3 applies.

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 ('Read') and resource ('an owned grant') and enumerates exactly what comes back: token_prefix, audience, approval, expiry, revocation, open_count. The explicit negative scope ('Does not download the file and does not return the share URL') separates it from sibling tools like fetch_shared_file and share_file.

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?

Clearly establishes context — read metadata for a grant you own, requires your API key — and rules out the download use case, which implicitly routes that need to fetch_shared_file. It stops short of naming the alternative tool explicitly or telling the agent where grant_id comes from (list_shares), so not a full 5.

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