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

Annotations already declare destructiveHint=true, idempotentHint=true and readOnlyHint=false, so the safety profile is covered. The description adds a failure mode the annotations cannot express: the FACT_IN_USE error and its resolution, plus the fact that draft usage also blocks deletion.

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, front-loaded with the action and then the blocking constraint and remedy. Every clause earns its place with no restatement of the title or schema.

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?

An output schema exists, so return values need not be explained, and annotations carry the destructive/idempotent profile. The description covers the critical precondition and error handling, leaving only auth/permission nuances (already in the schema) unaddressed.

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 name, blog_id and idempotency_key are fully documented in the schema (including the {{fact:...}} reference syntax). The description adds no parameter-level detail beyond that, so the baseline 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?

States a specific verb and resource ("Delete a live fact") that an agent can distinguish immediately from the sibling delete_post and delete_media tools. The "live" qualifier adds scope precision beyond simply restating the name.

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 an explicit when-not condition (a fact referenced by any post, drafts included, cannot be deleted) plus a concrete remediation path (edit the posts to write the figure as plain text). It stops short of naming the alternative tools (set_fact, list_facts) an agent might reach for instead.

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