discover_tools

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

Annotations already declare readOnlyHint=true and openWorldHint=true. The description adds context by listing categories and stating that already-active categories are returned. It clarifies the scope of activation (session-only) but could elaborate on whether activation has side effects. No contradiction with annotations.

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?

The description is concise and front-loaded, consisting of one purposeful sentence and a list of categories. Every element adds value without redundancy.

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 low-complexity tool with full schema coverage and annotations, the description covers purpose, parameter behavior, return information (active categories listed), and scope. No output schema is needed as return is described.

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% with clear description for the single parameter. The description adds critical guidance: 'Omit to list available categories', which is not in the schema. This provides necessary operational context.

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 clearly states the tool discovers and activates additional tool categories, with a specific verb ('discover and activate') and resource ('tool categories'). It lists all available categories and distinguishes itself from sibling tools which perform specific actions like create or delete.

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 explicitly explains when to use the tool: to discover and activate categories, and specifies that omitting the 'category' parameter lists available categories. It implicitly indicates not to use it for single actions, as siblings cover those.

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