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

Adds real behavioral constraints not present in the schema or annotations: up to 25 keywords per call, 2–9 words each, and the 'never-searched-yet go first' ordering on the next run. 'Sends nothing' usefully reassures the agent that this write operation causes no outbound email, complementing readOnlyHint=false. It doesn't cover duplicate handling or limit-violation errors.

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 short sentences, purpose and examples front-loaded, with limits and side-effect notes trailing. Every sentence carries information an agent needs; nothing is padding.

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 two-parameter add tool with no output schema and full annotation coverage, the description supplies purpose, examples, numeric limits, ordering behavior, and the no-send guarantee. Remaining gaps (duplicate keyword behavior, append vs. replace semantics, validation error shape) are minor.

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% (both params documented), so the baseline is 3; the description goes further by characterizing what a keyword should be (a search expected to surface link prospects) and imposing 25-per-call and 2–9-word constraints the schema lacks. It adds genuine meaning beyond the schema's 'exactly as typed into Google'.

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 ('Add Google searches for discovery to run') and grounds it with concrete examples ('vegan recipe blogs', 'write for us fitness'), so an agent knows exactly what is being created. The verb cleanly separates it from siblings list_keywords and remove_keywords.

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?

Explains the purpose context well: each keyword is a search that should surface sites that could link to this one, implying this is the entry point for link-building discovery. It does not explicitly name alternatives (list_keywords/remove_keywords) or state when not to use it, so it stops short of 5.

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