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

Annotations already declare readOnlyHint=false, destructiveHint=true, idempotentHint=true and openWorldHint=true, so the mutation/repeatability profile is covered. The description adds the genuinely useful fact that the pin is visible to the whole team, but says nothing about required permissions or how unpinning affects existing team state.

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 sentence that front-loads the primary action and appends the toggle behavior. Nothing is wasted and nothing essential is buried.

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?

An output schema exists, so return values need not be described, and annotations carry the safety profile. The remaining gap is the absence of any routing against pin_digest, but for a two-parameter toggle the description is otherwise sufficient.

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 only 50% — signal_id is documented in the schema but pinned is not. The description compensates by defining pinned=false as the unpin action (default true), giving the otherwise-undocumented parameter concrete meaning.

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 (pins) and resource (a signal), plus the inverse action via pinned=false. It does not differentiate itself from the sibling pin_digest, which shares the same verb, so an agent must infer the target distinction from the name alone.

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 description conveys when the tool is used (to pin or unpin) and that the effect is team-wide, but it offers no explicit when-not guidance or named alternative despite the near-identical sibling pin_digest. Usage is implied rather than routed.

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