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

With destructiveHint=true already in annotations, the description adds substantial value: atomicity by default with partial:true option, deduplication behavior on names, forking behavior for shared globals (returned id may differ, forkedFrom field), undoToken on delete, and restriction to deleting only non-global entries. This meaningfully extends beyond the annotation's bare safety flag. It doesn't contradict annotations.

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?

The description is dense but organized: it opens with the core action, then systematically covers operations, validation (patterns, colors, dedup), delete constraints, atomicity, and workflow linkage. It's longer than ideal but every sentence carries meaningful information with no filler — appropriate for a complex multi-mode tool.

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?

Given the tool's complexity (two object types, three operations each, maxItems constraints from schema, no output schema), the description covers nearly all operational behavior: dedup rules, forking, atomicity, delete safeguards, and downstream usage in write_events. Minor gaps like exact response shape and what undoToken does aren't specified, but the agent has enough to invoke 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 only 33%, so the description must carry significant weight — and it does. It explains the op enum pattern ({op:'create'|'update'|'delete'}), the color vs pattern difference between areas and activity types, valid pattern values, 6-digit hex color format, auto-pick on omission, reassignTo semantics, and the partial flag. This substantially compensates for the low schema coverage.

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?

The description clearly states this tool creates, updates, or deletes areas and activity types, with specific verbs and resources. It distinguishes itself from write_events (referenced explicitly: 'Create areas/types here first, then reference the returned ids in write_events') and sibling tools like manage_backlog and delete_events, making its scope unmistakable.

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?

The description gives strong usage context: create first then reference ids in write_events, delete only own non-global entries, use reassignTo when events still use an entry. It doesn't explicitly contrast against sibling tools that might overlap, but the contained guidance is thorough for setup-before-use.

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