list_messages

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds the server-side cap at limit 200, which is useful behavioral context beyond annotations. It does not mention pagination or return format, but with the output schema present and safety annotations, this is adequate.

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 two sentences, front-loaded with the main action and then the key constraint. It is concise and directly useful, with no wasted words. The only slight deduction is that the mention of 'name, ID, or sender' might be overly specific if 'search' is a generic filter, but it stays within a reasonable length.

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?

Given the tool's simplicity (3 params, output schema present, read-only annotations), the description covers the essential behavior: listing messages with optional filters and a limit cap. It doesn't explain output structure but the output schema covers that. The main gap is lack of explicit distinction from siblings, but overall the description is adequate for a read-only list tool.

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. It mentions narrowing by name, ID, or sender, which maps loosely to the 'search' parameter, but it doesn't explicitly explain the 'limit' or 'dbc_path' semantics beyond what the schema names imply. The description adds some meaning but not enough to fully compensate for zero schema coverage, hence a 3.

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 states it lists DBC messages and mentions optional narrowing by name, ID, or sender, which clearly identifies the verb+resource and scope. It does not explicitly distinguish from siblings like 'get_message' but the resource is clear. The sibling tool 'get_message' is presumably for a single message, so the plural list is implied but not explicitly differentiated.

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 description implies usage for listing messages with optional filters, but it does not explicitly state when to use this versus alternatives like 'get_message' or 'search_signals'. No exclusions or alternatives are mentioned, so while context is clear, there is no direct comparison to sibling tools.

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