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

Annotations only say readOnlyHint=false and destructiveHint=true; the description adds rich behavior beyond that: emails on crossing, again on return, once if the check starts failing, silence while staying across the line, org-member recipient constraint, default-to-self, at-most-hourly cadence, and upsert-on-repeat (which explains the destructive overwrite hint). This is exactly the extra context annotations cannot carry.

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?

Dense but every clause is load-bearing — purpose is front-loaded, then semantics, recipients, cadence, upsert, and the disable sibling. No filler or repetition.

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 fully carries the burden: it explains trigger conditions, email behavior, recipient rules, cadence limits, and update behavior. An agent can call it correctly without further inference.

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 63%, and the description compensates meaningfully: it defines the column fallback ('first numeric column when none is named'), the op comparison set, the default recipient behavior, and cadence/timezone reading. projectId and queryId are left to their schema descriptions, so not a full 5.

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+resource and scope: 'Watch one number from a saved query and email when it crosses a line.' It clearly separates itself from sibling creation tools (create_query, create_report, create_dashboard) by naming the alerting/threshold behavior.

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?

Gives clear usage context — it executes a saved query on each run, and 'The same query and condition asked again updates the timetable and recipients' defines upsert semantics. It also names the alternative fastero_set_schedule_enabled for switching off. No explicit when-not-to-use beyond that, so a 4 rather than 5.

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