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

Annotations already cover the safety profile (readOnly, non-destructive), so the description earns credit by adding non-obvious behavior: messages come back oldest-first, attachments are name-only with no content, and a Cotlet API key with app access is required. The ordering and attachment limitation are genuinely useful details an agent could not infer from annotations.

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?

Four compact sentences, front-loaded with the tool's function before the return-shape and auth details. Minor redundancy between 'Messages in one conversation' and 'the most recent messages of one conversation,' but nothing is padded.

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 two-parameter read tool with no output schema, the description covers the return fields, ordering, attachment handling, and the API-key prerequisite. An agent has everything needed to call it correctly; only explicit sibling routing is missing.

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%, so both parameters are already documented, including limit (1-200, default 50) and conversation_id provenance. The description reinforces the 'most recent messages' semantics of limit, but adds no format or edge-case detail beyond what the schema provides — 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 ('Get conversation') and then specifies exactly what it returns: messages with sender, time, and attachment names. It is clearly a single-thread read, but it never names its sibling (trainerize_list_conversations), so differentiation relies on the schema rather than the description.

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?

Usage is implied: fetch 'the most recent messages of one conversation,' which tells the agent it needs a conversation ID first. However, it never states when to pick this over list_conversations or how it relates to a broader inbox flow; that routing hint lives only in the parameter description.

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