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

Annotations already declare readOnlyHint=false, openWorldHint=true and idempotentHint=false, so the write/open-world nature is covered structurally. The description goes well beyond them by disclosing quota consumption, the free-repeat cooldown, cached stale responses with a `meta.note` to relay, and plan/auth requirements — genuinely useful operational context. It stops short of describing the candidate list shape or how ranking works, so a 3 rather than higher.

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?

Front-loaded with the "WRITE tool" marker and the core action before operational caveats. Dense with parentheticals (cooldown, allowance, plan requirement) which are individually load-bearing but make the prose heavier than it needs to be.

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 no output schema, the definition covers the action, the follow-up workflow, cost/quota behavior, cached-result fallback, and access requirements. Nothing an agent needs in order to invoke it correctly and interpret the outcome is missing.

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%, and all three parameters carry their own descriptions including the channel enum. The description reinforces channel semantics ("meta" for Facebook, "tiktok" for TikTok) but adds no syntax or format detail beyond the schema, so the baseline of 3 applies.

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?

Opens with a specific verb plus resource ("search a competitor's Facebook page ... or TikTok account") and names the return shape (ranked candidates with a `best_match` flag). It explicitly negates the neighboring capability ("never links"), so an agent can separate it from sonar_ad_spy_link and sonar_ad_spy_search_pages without opening the schema.

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?

States the follow-up action explicitly: show candidates, let the user confirm, then call sonar_ad_spy_link, with the rationale that the mapping is account-shared. It also gives exclusions and edge conditions (unambiguous top match, free 24h cooldown replay, same-day re-open free, stale fallback past allowance), which is the full when/when-not picture.

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