get_thread

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

With zero annotations provided, description carries full disclosure burden excellently. Reveals implementation algorithm (subject matching + References/In-Reply-To headers) and platform-specific limitation (iCloud lacks server-side threading, results approximate). No contradictions with 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?

Three sentences with zero waste: sentence 1 states purpose, sentence 2 reveals implementation method, sentence 3 warns about platform limitation. Front-loaded with action and resource. Efficient density of 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?

Given no annotations and no output schema, description adequately covers behavioral complexity (threading logic, header parsing, platform variance). Missing only minor details like return format or error handling for invalid UIDs, but explains the critical approximation caveat for iCloud users.

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?

Input schema has 100% description coverage (uid defined as 'Email UID to find the thread for', mailbox as 'Mailbox to search'). Description implies uid references the anchor email but doesn't add syntax, format constraints, or validation rules beyond schema. Baseline 3 appropriate given complete schema documentation.

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?

Description opens with specific verb 'Find' + resource 'emails' + scope 'in the same thread as a given email', clearly distinguishing from sibling get_email (single email retrieval) and search_emails (general criteria search). The threading concept is unambiguous.

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?

Provides important technical context about iCloud limitations and result approximation, implying reliability concerns. However, lacks explicit guidance on when to use this versus search_emails or get_email for conversation reconstruction, and doesn't specify prerequisites like UID validity.

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