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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered by structured data. The description adds that incoming requests are the default view, which is useful behavioral context. It says nothing about result volume, pagination, ordering, or the shape of the returned list despite having no output schema.

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?

Two short sentences, front-loaded with the core action, then the filter vocabulary, then the routing note. No filler and nothing redundant.

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 read-only, three-parameter list tool with no output schema, the description covers the two filterable dimensions that matter and the action it is not responsible for. The missing piece is any guidance on 'limit' or result size, which an agent would need to avoid over- or under-fetching.

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 0% and no parameters have enums, so the description is the only source of allowed values — and it supplies them for two of three params (direction: incoming/outgoing; status: pending/all) with their defaults. The 'limit' parameter is left entirely undocumented, keeping this below a 5.

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 and resource ('List friend requests') and immediately distinguishes the scope of what it does not do by pointing out that accepting/declining happens by request id elsewhere. It stops short of naming accept_friend_request/decline_friend_request explicitly, so the routing is implied rather than explicit, but the agent can still tell this is a read-only listing tool.

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 the defaults for both filters (direction=incoming, status=pending) which is exactly the context an agent needs to know whether to pass parameters at all. It also signals that mutating actions belong to the accept/decline tools, giving an implicit exclusion. It does not name those sibling tools directly, so the alternative is inferred.

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