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

Annotations already declare readOnlyHint=false, destructiveHint=false and openWorldHint=false, so the safety profile is covered structurally. The description adds nothing beyond that: it does not say whether duplicate keywords are merged, whether the operation is idempotent, what project/site scope is required, or anything about the result of a bulk add.

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?

A single front-loaded sentence with no filler; the problem is under-specification rather than verbosity. It reads cleanly but is arguably too terse for a 3-parameter mutation tool.

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 three-parameter write tool with zero schema descriptions and no output schema, the description omits almost everything an agent needs: project/site targeting context, dedup behavior, and confirmation of effect. The per-item constraints (maxItems 100, maxLength 200) exist only in the schema and are never surfaced.

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 0% across three required parameters, so the description must carry the burden and largely fails. It implies the phrases array ('keywords') but leaves projectId and siteId completely unexplained, forcing the agent to guess at the scope of the write.

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 gives a specific verb plus resource (add keywords) and scopes it to link prospecting, so the agent can tell it targets outreach/prospecting keywords rather than article or lead keywords. It does not name the sibling it differs from (add_article_keywords, create_lead_keyword), so it stops short of a 5.

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?

There is no when-to-use guidance and no alternatives cited, despite siblings list_outreach_keywords and remove_outreach_keyword existing. The agent must infer that this is the create-side of the outreach keyword lifecycle without any stated condition or prerequisite.

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