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

Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false), so the bar is lower. The description goes beyond them by disclosing the returned fields and, importantly, the last_check status domain (running | completed | partial | failed, with its error) — meaningful behavioral detail that no output schema provides. It omits pagination/truncation behavior beyond what the schema says.

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 tight sentences, with the core list-and-contents statement front-loaded before the workflow cue. The trailing 'Recall the agreed targets...' sentence is slightly editorial but still earns its place as usage context.

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?

With no output schema, the description carries the return-value burden and does so adequately by naming the fields and the last_check status values. It is complete enough to invoke correctly, though it could say more about list size/pagination or the default concise behavior.

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 site_id and the detail verbosity parameter are already documented in the schema (including the top-25 trimming rule). The description adds no parameter-level detail, so the baseline 3 is appropriate.

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 opens with a specific verb+resource ('List the keywords tracked for a brand') and immediately scopes what is returned (search volume, difficulty, rank position, last_check status). It is clearly distinguishable from add/remove/check siblings by being the read/list operation, but it never names or contrasts with those siblings explicitly.

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?

'Recall the agreed targets before building or optimizing pages' gives a concrete workflow context for when to call it. However, it offers no when-not guidance and does not mention alternatives such as tracked_keyword_performance or check_tracked_keyword_rankings, so usage remains implied rather than routed.

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