Thinking

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

The description discloses a write operation ('append'), consistent with readOnlyHint=false. However, it does not elaborate on side effects, persistence of the scratchpad, or any behavioral traits beyond the basic purpose, which is acceptable but not thorough.

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 concise: a single sentence for purpose, a usage guideline, and two examples. It is front-loaded with the core action and wastes no words.

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 (9 parameters, no output schema), the description is incomplete. It covers purpose and usage but fails to explain the full parameter set or behavioral nuances, such as how branching and revisions work.

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?

With 0% schema description coverage and 9 parameters, the description only provides examples for a few (thought, thought_number, total_thoughts, next_thought_needed). Parameters like branch_id, is_revision, revises_thought, branch_from_thought, and needs_more_thoughts are not explained, leaving significant gaps for agent invocation.

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 'Append a thought to internal scratchpad,' providing a specific verb and resource. It distinguishes from sibling tools like autofix or plan by focusing on internal reasoning, and the 'USE WHEN' clause reinforces this differentiation.

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?

It explicitly says 'USE WHEN: Agent needs reasoning before action or multi-step deliberation,' giving clear context for use. It lacks explicit when-not-to-use or alternatives, but the context is sufficient for most cases.

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