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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered by structured data. The description adds the filter criteria and the return fields, which is useful, but says nothing about pagination behavior, ordering, or empty-result handling — relevant for a list tool with a cursor parameter.

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 compact sentences: purpose, return shape, usage guidance. Front-loaded with what the tool does. The Cotlet API key sentence is slightly bolted-on but relevant. No filler.

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?

Covers purpose, filters, returned fields, and a usage scenario, which is enough for an agent to call this read-only tool correctly. The auth requirement is mentioned. A minor gap: no mention of page size default (though the schema has it) or pagination behavior despite the cursor parameter.

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 100%, so the schema already documents text, limit, cursor, entry_type and journal_number. The description's mention of 'filtered by type, text or voucher number' loosely maps to schema fields but adds no syntax or format detail. Baseline 3 is correct.

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: 'Entries in a journal, filtered by type, text or voucher number.' An agent knows exactly what is returned (account, contra account, amount, date, text, voucher number). It does not name a sibling list tool or differentiate from them, but the purpose itself is unambiguous.

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 an explicit use case: 'Use it before posting to see whether a voucher already exists.' This tells the agent when it is the right tool. It stops short of naming when not to use it or naming a specific alternative sibling, so it is not a 5.

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