yahoo_get_mail

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

With no annotations, the description must carry the behavioral burden, and 'Read' does signal a non-mutating operation. It also documents useful defaults (folder=INBOX, body=text, max_body_chars=5000) and the truncation behavior. However, it says nothing about auth/permission requirements, rate limits, or what happens when a UID is absent.

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 purpose is front-loaded in the first line, followed by a compact args list where each entry earns its place. The structure is clean and proportionate to a 5-parameter tool, with no filler.

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?

An output schema exists, so return formatting need not be described, and the description fully documents inputs. What remains thin is behavioral context (permissions, error/edge behavior) for a tool with zero annotation coverage, but for a simple read operation the definition is largely sufficient.

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 description coverage is 0%, so the description is the only source of parameter meaning, and it covers all five parameters: msg_id provenance, folder default, body format options (text/html/none), truncation limit, and the account key from accounts.json with its default. This meaningfully exceeds the bare schema and enables correct 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?

States a specific verb and resource ('Read a specific message by UID') and ties it directly to the sibling tools that produce the UID ('the "id" from yahoo_list_mail or yahoo_search_mail'). An agent can distinguish this fetch-by-id tool from the list/search siblings without opening any schema.

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 clearly establishes the workflow context by stating the msg_id comes from yahoo_list_mail or yahoo_search_mail, implying this tool is used after a listing/search step. It does not, however, state explicit exclusions or alternatives (e.g., when to prefer search over this).

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