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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and closed-world, so the safety profile is covered. The description adds non-obvious context: it requires a New Site Radar Pro API key with specific header formats and a documentation URL, which is important operational detail not captured by annotations. It does not describe rate limits or failure modes, keeping it short of a 5.

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 a dense but well-structured sequence: purpose, search inputs, return fields, prerequisite pointer for categories, and authentication. Every clause carries information, though the auth URL and header formats make it slightly heavier than strictly necessary for selection.

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 7-parameter read-only search tool with no output schema, the description covers purpose, filter surface, returned fields, prerequisite category lookup, and authentication requirements. It omits pagination behavior and whether results are sorted, which are minor for this complexity level.

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 every parameter including enums and defaults is already documented in the schema. The description summarizes the filter categories (category, site type, monthly-visits bucket, MoM bucket, payment detected) and the keyword fields but adds no syntax or nuance beyond what the schema provides. Baseline 3 is appropriate when the schema fully covers parameters.

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 (Search) and resource (current monthly board of new AI tool sites), and spells out exactly what is searched (keyword on domain/name/description) and what filters exist. It is clearly distinguishable from siblings like get_site (single site), top_rising, or model_releases because it is the only board-search tool.

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?

It gives clear context for use, including the supported filter dimensions and an explicit pointer to list_categories for valid category slugs. It does not state exclusions (e.g., use get_site instead when you already know the domain), but the context is strong enough for an agent to select it over siblings.

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