todo_update

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

Annotations already declare the profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false, openWorldHint=false), so the bar is lower. The description adds the useful note that the call returns the updated list and names the legal status values, but it doesn't address what happens when a field is null/omitted or why the operation is flagged non-idempotent.

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?

A single clause-packed sentence with zero waste, front-loading the verb and the mutable fields before the return-value note.

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 tool is small (3 params, 1 required) and an output schema exists, so return values need not be described further. The description covers the mutable surface adequately; the remaining gaps are edge-case semantics (nonexistent id, omitted vs null fields) rather than missing essentials.

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 0% and the schema contains no enum for status, so the description's enumeration (pending, in_progress, done) supplies meaning the schema genuinely lacks. However, it says nothing about the id parameter (must reference an existing todo?), whether text replaces or appends, or how null defaults behave for the two optional fields.

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?

"Change a todo's status ... and/or text" gives a specific verb plus resource and enumerates the mutable fields, which is enough to distinguish it from todo_add, todo_list and todo_remove without opening the schema. It stops short of naming those siblings explicitly.

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: 'change' versus add/list/remove is inferable from the name and sibling set, and 'and/or' hints at partial updates. There is no explicit statement of when to prefer this tool, no prerequisite (the id must already exist), and no error guidance.

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