Mark recruiter messages read

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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the mutation is flagged. The description adds the crucial detail that 'the change has no undo' (irreversibility) and that only the listed messages are affected, which goes beyond what the annotations convey.

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 short sentences, front-loaded with the action and scope, then the effect, then the irreversibility warning. Every sentence carries distinct information with no repetition of the name or schema.

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?

An output schema exists so return values need no explanation, and annotations cover the safety profile. For a two-parameter mutation tool, the description supplies scope, effect on other messages, and irreversibility — everything needed to call it correctly.

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 the baseline is 3. The description nevertheless adds meaning by explaining what messageIds represent ('the exact messages presented to the account holder') and constraining threadId to a single thread, clarifying the intended values beyond the schema text.

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 (marks read) and resource (recruiter messages) with an explicit scope boundary ('within one thread'). The clause 'other messages remain unread' pins down exactly what is and isn't affected, which separates it cleanly from siblings like get_inbox and get_unread_reminders.

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 only implied: the reference to 'messages presented to the account holder' and the schema note 'as get_inbox gave it' suggest this follows a get_inbox call. There is no explicit when-to-use statement, no prerequisites, and no named alternative, though no sibling competes for this action.

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