read_message

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

With no annotations, the description carries the full burden, and it does disclose two real behaviors: content is pseudonymized and attachment bodies are not fetched. It omits other consequential behavior — whether reading marks the message as read (a separate mark_read sibling exists, implying it does not), permissions, and error behavior when the id is invalid.

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?

Two short sentences, no filler, and the scoping limitation is stated up front as a caveat. Every sentence earns its place.

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 one-parameter read tool with no output schema, the description covers the essential caveats (pseudonymization, no attachments) but leaves return shape and the meaning of message_id unexplained. Adequate but with clear gaps.

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% for the single parameter, so the description must compensate and does not: message_id is never mentioned or illustrated (format, source of the id from list_messages/search_messages results). The only implicit signal is that the tool takes an id at all.

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 ('Läs ett helt meddelande'), and the qualifier 'helt' vs the list/search siblings implies full-body retrieval. It does not explicitly contrast itself with list_messages or search_messages, so differentiation is inferred rather than stated.

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?

No guidance on when to use this versus search_messages or list_messages, and no prerequisites (e.g. whether the message must be in the inbox first). The 'helt meddelande' phrasing hints at a fetch-by-id use case, but nothing explicit.

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