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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered; the description adds genuinely useful non-obvious behavior by clarifying that the decryption key is never returned and only exists client-side in the human's browser. It does not cover what happens if the share is revoked, expired, or nonexistent, so it stops short of full transparency.

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 compact sentence with zero filler, and the most decision-relevant constraint (no decryption key) is placed where the agent will read it immediately.

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?

For a one-parameter read tool with complete schema coverage and read-only annotations, the description covers the essential nuance about the missing key. The remaining gap is error/absence behavior for revoked or unknown share ids, which is minor but non-trivial.

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 coverage is 100% and the single share_id parameter is documented as a uuid in the schema itself, so the description adds no parameter-level meaning. Baseline 3 applies since the schema carries the burden.

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 the specific resource (one share's details and its link) and a distinguishing property: the decryption key is excluded. An agent can tell it apart from list_shares and the share-mutation siblings, though the verb itself is only implied rather than stated.

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 single-share scope is implied by 'One share's details' and the required share_id, but there is no explicit when-to-use guidance, no mention of when to prefer list_shares, and no note on prerequisites such as the share still being active.

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