cos_work_log_append

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

Annotations already indicate a non-read-only, non-idempotent write operation (readOnlyHint=false, idempotentHint=false), so the description needs to add additional behavioral context. It does not; it merely restates the append behavior and gives a vague 'Critical' note with no details on side effects, permissions, or error handling.

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?

The description is concise at two sentences and front-loads the primary purpose. The second sentence, 'Critical for Codex sessions,' adds context but is not strictly necessary; overall the description is efficiently structured without wasted words.

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 simple append tool with annotations and an output schema, the description covers the basic action adequately. However, it leaves gaps in parameter semantics and does not mention error conditions, prerequisites, or how the output is returned, making it minimally complete but not thorough.

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 0%, so the description must compensate by explaining parameters. It does not. While 'task_id' and 'summary' are somewhat self-explanatory, the purpose of 'source' and 'agent_session' is not clarified, and the description provides no parameter-level guidance whatsoever.

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?

The description uses the specific verb 'append' and identifies the resource as 'Work Log line to a task', which is clear and distinct. It effectively differentiates from sibling tools that read, query, or edit tasks, and adds context by calling it 'Critical for Codex sessions'.

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?

The phrase 'Critical for Codex sessions' provides some context for when to use the tool, but it does not explicitly compare to alternatives or state when not to use it. The guidance is implied rather than concrete, leaving the agent uncertain about the exact conditions.

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