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

Annotations only say readOnly=false and destructive=true; the description adds the real behavioral facts: a hard 60-minute edit window, a product-type restriction, a 100/day allowance, and the fact that the recipient sees the new text. The rate limit and human-visible side effect are exactly the context annotations cannot convey.

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 short sentences, each carrying a distinct constraint (scope, eligibility, consequence/rate limit) with the core action front-loaded. No filler or restatement of the name.

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?

A destructive mutation with no output schema and full schema coverage; the description supplies time window, product limits, rate limit and visibility. It does not say what happens on failure (e.g., past the window or over quota) or whether the edit is marked as edited, which would round it out.

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% and all three parameters are documented in-schema (including the messageId -> list_chat_messages pointer and the connectionId fallback). The description adds no parameter-level detail, so the baseline of 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 ('Change the text of ONE message you sent on LinkedIn') and pins down scope with 'ONE' and 'you sent', which cleanly separates it from send_message, delete_message and edit_job_posting. An agent can identify the operation without opening the 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?

Gives explicit eligibility conditions: within 60 minutes of sending and only for ordinary messages, not Sales Navigator or Recruiter. It does not name the alternative to use when those conditions fail (e.g., delete_message or send_message), so the when-not path routes nowhere.

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