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

With destructiveHint=true already declared, the description adds real context: access is validated first, the binding persists across calls, and the tool only works on API-key requests. However, it never explains what 'destructive' means here — whether a previously bound project is replaced or whether the binding affects other keys — leaving the riskier part of the behavior unstated.

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, front-loaded with the core effect (binding to the API key) before the persistence and availability caveats. Every clause carries information.

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, no-output-schema tool this covers the essentials: what it does, where it applies, persistence semantics, and the access check. The remaining gap is overwrite/unbind behavior, which matters given the destructive annotation.

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 projectId field already documents the UUID and points to list_projects. The description adds no parameter-level meaning beyond the schema, so the baseline of 3 applies.

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 — 'Binds a project to this API key' — plus the scope (rest of the MCP session, persisted for the key). This is clearly distinguishable from siblings like get_active_project and list_projects.

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 concrete conditions: 'Only available on API-key MCP requests' and that the binding removes the need for the X-Project-Id header, which implies when to reach for it. It does not name alternatives (e.g., use the header per-call, or the OAuth/session path) or state exclusions explicitly.

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