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

Annotations already declare readOnlyHint=false, destructiveHint=false and openWorldHint=false, so the write/safety profile is covered. The description adds value beyond that by disclosing a side effect annotations cannot express: mentioning users rings their notification bell, with an accompanying social caution. It omits permission/auth requirements for posting.

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?

Front-loads the core action and its two modes, then layers usage and mention etiquette compactly. Two sentences, minimal waste, though the trailing 'never mention someone who didn't ask' is advisory padding rather than invocation-critical 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 7-parameter mutation with 43% schema coverage and no output schema, the description covers the social/mention dimension well but leaves the entity-targeting parameters and the undocumented approvalId unexplained, which an agent would need to call this reliably in all cases.

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 only 43%, so the description must compensate, and it partially does: rootId (reply target), mentionedUserIds (workspace member ids, notification behavior), and body are implied. However entityKind's 17-value enum, entityId, and especially approvalId are unexplained in both schema and description, leaving real gaps.

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 precise verb and resource ('Posts a comment on a workspace entity') and distinguishes the two modes of operation: new thread vs. reply when rootId is given. It never names its closest siblings (comments_list, comments_resolve), so it stops just short of a 5.

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 concrete usage context ('leave findings where the discussion already lives') with two illustrative scenarios (eval result on a debated flow, summary on a long thread). It does not state when not to use it or point to a sibling alternative, so it lacks the explicit routing of a 5.

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