Discover content types

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

Annotations already mark this as read-only and non-destructive. The description adds meaningful behavioral context: the show_in_rest => false implication for absent types, which informs the agent about the tool's scope and limitations. It does not contradict the annotations (idempotentHint false is plausible for a listing that may reflect changing data, but the description doesn't claim idempotency). No conflicts.

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?

Two sentences with zero waste. The primary action is front-loaded, followed by precise usage guidance. Every clause earns its place—no redundant phrases or fluff.

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 listing tool with no output schema, the description fully explains what is returned and why this tool is essential for unfamiliar sites. It also covers the show_in_rest behavior and the optional include_counts parameter is already in the schema. An agent can call this correctly without additional information.

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 both parameters (site_id, include_counts) are fully documented in the schema. The description does not add any parameter-specific details beyond the schema; it only mentions the include_counts cost indirectly via the parameter description. Per the rubric, a baseline of 3 applies when the schema carries the semantic weight.

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 states a specific verb ('List'), a clear resource ('every content type registered on the site'), and enumerates the exact attributes returned (REST base, hierarchical status, taxonomies, supported fields). This distinguishes it from sibling tools like discover_taxonomies, which target a different resource. The purpose is unambiguous and detailed.

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 gives explicit context for when to use it: 'Call this before working with an unfamiliar site.' It also explains the consequence of a type being absent (show_in_rest false and unreachable via REST), which is valuable guidance. However, it does not explicitly name alternatives like discover_taxonomies or state when *not* to use it, so it lacks formal exclusions/alternatives.

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