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

Annotations declare destructiveHint=true and readOnlyHint=false, so the safety profile is already covered. The description adds the genuinely useful side-effect disclosure that the FK field on the source side is preserved, which is the main behavioral question an agent would have about a relation deletion. It does not cover reversibility or downstream effects, keeping it short of a 5.

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 action front-loaded and the disambiguating side-effect second. No filler, no restatement of the title.

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 two-parameter tool with no output schema, the description plus annotations cover what is destroyed and what is not. It leaves unstated whether deletion cascades to dependent entities or is recoverable, which a cautious agent would want, but the essential invocation-relevant facts are present.

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 'id' and 'expectedProjectId' are already documented in the schema, including the refusal behavior on unauthorized project targeting. The description only echoes the FK-preservation note that also appears on the 'id' parameter, so 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?

States a specific verb and resource ('Deletes a relation') and immediately distinguishes itself from the closest sibling by clarifying that the FK field survives, unlike delete_field. An agent can route between delete_relation and delete_field without opening either 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?

Explicitly names the alternative (delete_field) and the condition that differentiates it: this tool leaves the FK column intact, delete_field removes it. There is no explicit 'use this when' framing, but the contrast gives clear selection guidance.

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