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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the write profile is covered. The description adds the state restriction on which posts are mutable, which is useful. It does not disclose whether omitted fields are cleared, permission requirements, or reversibility, so the added value is modest.

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 short sentences, zero filler, with the mutation and the eligibility precondition front-loaded. Every sentence earns its place.

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 no explanation, and annotations cover the destructive profile. However, for a tool with a nested per_account object and two undocumented parameters, the description is thin on how per-account text vs first_comment vs content interact.

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 only 40% and the description names just two of five parameters (content, scheduled_time), without format or field-level detail beyond what the schema already says. The nested per_account object and first_comment are undocumented in both the schema and the description, so the description fails to compensate for the coverage gap.

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 (update a post) plus the two editable areas (content, scheduled time) and the eligible post states. It does not name a sibling to distinguish from (create_post, duplicate_post, delete_post), but the purpose is unmistakable.

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?

"Only pending/draft posts can be updated" gives an explicit precondition that tells the agent when the tool will fail, which is genuine usage guidance. It stops short of naming alternatives (e.g., use approve_draft to publish, get_post to inspect) but the constraint is clear.

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