read_message

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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so safety is covered. The description adds non-obvious behavior beyond the structured fields: the response carries a next_offset field and the read is incomplete until that value is null — critical since there is no output schema declaring it.

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 with zero filler; the core operation is front-loaded and the pagination instruction follows immediately. Nothing could be removed without losing information.

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?

The pagination contract is covered, which is the single most important thing given no output schema exists. But the description omits the units/limits of offset, the identity of 'id', and any routing guidance among the many sibling read tools — gaps that matter for a chunked-read 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 carry the load. It clarifies that 'offset' is a starting position within the message, but never states what 'id' identifies (message id) or what units the offset uses (characters, bytes, tokens), leaving ambiguity for a caller resuming a partial read.

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 ('Read a long message') plus the chunking scope ('from offset'), so an agent knows this is a paged read rather than a whole-message fetch. It does not differentiate from siblings like 'view', 'zoom', or 'compact_read', which plausibly also return message content.

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?

'Follow next_offset until it is null' is genuinely useful procedural guidance for driving the pagination loop. However, there is no statement of when to choose this over 'view' or 'compact_read', nor any precondition about the message needing to be long.

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