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

Annotations already declare destructiveHint=true and idempotentHint=true, so the mutation/idempotency profile is covered. The description adds genuinely new context beyond them: the tool only applies to messages in an already-hidden state and should be invoked on explicit user request only, which is behavioral guidance the annotations cannot convey. It stops short of disclosing side effects such as the bulk unhide path or how the message state changes afterward.

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 sentences, no filler. The purpose and the sibling relationship are front-loaded, followed by the usage constraint; every clause carries distinct 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?

For a three-parameter mutation tool with no output schema and full schema coverage, the description supplies purpose, sibling disambiguation and an explicit consent guardrail. What's missing is any note on the consequences of unhiding or of the bulk flag, which would matter given destructiveHint=true.

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 logId, messageId and the markAllAsUnhidden flag are fully documented in the schema. The description only echoes 'by ID' and adds no syntax, format, or guidance for the bulk flag, so the baseline 3 applies.

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 (unhide) plus resource (a previously hidden log message) and its key input (by ID). It explicitly positions itself against a sibling, 'the opposite of messages_hide', so an agent can distinguish it from the hide/get/list tools without opening a schema.

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 when-to-use rule with a hard exclusion: 'Only call this when the user has explicitly asked to unhide this message — never speculatively while just investigating errors.' This is exactly the kind of guardrail an agent needs to avoid inadvertently reversing a deliberate hide, and it names the sibling it mirrors.

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