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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, and the description adds meaningful behavioral context beyond them: it is public, requires no credentials or arguments, returns metadata only, and does not fetch stories or check upstream freshness. The separate mobile app suspension note also discloses an important scope limitation. No contradiction with annotations exists.

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?

Four sentences, each carrying distinct information: purpose, return type and exclusions, authentication/argument requirements, and sibling routing. The most important usage context is front-loaded, and there is no fluff or repetition of schema details.

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 zero-argument, read-only metadata tool with no output schema, the description is complete: it states what is returned, what is intentionally not performed, access constraints, and which sibling tools cover adjacent use cases. An agent has enough context to decide to call it and interpret its result safely.

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?

There are no parameters and the schema already documents this with additionalProperties false. The description reinforces this by stating 'no credentials or arguments,' which is a useful confirmation, but the schema already carries the full semantics.

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 uses a specific verb and resource: 'Discover available product features, API/MCP URLs, versions, content limits, and interpretation boundaries.' It clearly distinguishes this tool from content-fetching siblings by stating it returns product.capabilities.v1 metadata 'without fetching stories or checking upstream freshness.'

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?

Explicit guidance is provided: use this tool 'before choosing a content tool,' and alternatives are named directly—'Use latest_stories for recent records or get_health for endpoint compatibility.' This tells an agent exactly when this tool is appropriate and when to route elsewhere.

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