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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and a closed world, so safety is covered. The description adds genuine value by disclosing the two possible return shapes (a per-person count versus titles), which matters because there is no output schema; it says nothing about pagination or limits, 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?

A single compact sentence that front-loads the default behavior and then the parameter-conditioned variant. No filler, no repetition of the title.

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 carries the return-value burden and does describe both output modes, plus it implies user-scoped authorization. Minor omissions remain (pagination, whether counts cover all share types), but an agent has enough to call it 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?

Schema description coverage is 100%, so the baseline is 3, but the description goes beyond the schema's 'Name or email of a team member' by explaining the functional effect of supplying `person` — the result switches from counts to titles shared with that person. That is real semantic added value.

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 states a specific verb and resource ('Shows what the user currently shares') and scopes it to the authenticated user, which clearly separates it from share_with and share_revoke in the sibling list. It does not name those siblings explicitly, so it falls just short of a 5.

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?

It implicitly describes two usage modes (no argument = count per person; with `person` = titles shared with that person), which is enough to know how to call it. It never states when to prefer this over share_with, share_revoke, or team_list, so usage guidance remains inferred rather than explicit.

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