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

The annotations declare destructiveHint=true, while the description explicitly characterizes the operation as 'additive' and states it 'sends no message' — a direct negation of the destructive semantic the annotation asserts. Per the scoring rule, a description that contradicts annotations scores 1 and is flagged.

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 with the core action front-loaded and no padding. The trailing 'Bird API: POST /v1/audiences' is marginally useful context for API-aware agents but is largely restating what the tool does.

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 simple three-parameter create tool with no output schema, the description covers the essential add-audience behavior and the static-empty caveat. It does not say what comes back (e.g. the new audience identifier), whether contacts can be attached at creation time, or anything about permissions, and the conflict with destructiveHint leaves the safety profile ambiguous.

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 schema already documents name, type (with an enum) and description, giving a baseline of 3. The description only adds the fact that 'static audiences start empty', which touches on the type parameter but adds no format or constraint detail beyond the schema.

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 gives a specific verb+resource ('Creates an audience (contact list) in Bird') and clarifies the resource type, making it distinguishable from list/get siblings and from the message-sending tools. However, it never names a sibling it is not, so differentiation is more implicit than explicit.

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?

There is no when-to-use guidance, no prerequisites, and no mention of alternatives such as bird_create_contact or bird_list_audiences. 'Static audiences start empty' is a behavioral fact rather than a usage routing cue, leaving the agent to infer the call context.

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