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

Annotations only flag readOnlyHint=false, destructiveHint=true and idempotentHint=true; the description goes well beyond them by disclosing the destructive cascade (every report, dashboard chart and alert reads the new SQL from its next run), that charts plotting dropped columns stop drawing, and that the old SQL is not retained. It also carries a required conditional behavior: resend definitionsUsed so it is restamped at the current version.

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?

Three sentences, all information-dense, with the mutation and its field scope front-loaded before the downstream side effects. Each sentence carries unique content, though the phrasing is slightly dense and the definitionsUsed rule arrives last rather than being surfaced as a hard requirement.

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 destructive, no-output-schema mutation tool, the description covers the field-level semantics, an immutable field, downstream side effects, dropped-column behavior, loss of the old SQL, and the version restamping requirement. Nothing an agent needs to call it safely 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 coverage is 100%, so the per-parameter meanings are already documented and the baseline is 3. The description adds conditional semantics the schema cannot express: definitionsUsed must be resent specifically when SQL changes, and the sql parameter carries the read-only constraint rather than arbitrary SQL.

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 ('Change a saved query's name or SQL text') and immediately scopes the operation by naming the two mutable fields and excluding connection changes. An agent can distinguish this from fastero_create_query, fastero_delete_query and fastero_get_query without opening any 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?

Explains the partial-update rule ('fields not sent stay as they are') and an explicit exclusion ('its connection cannot be changed here'), and cross-references fastero_create_query for the read-only SQL constraint. It does not spell out when to prefer create-vs-update or any prerequisite permissions, 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.