Microsoft MCP

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states the tool sends emails 'immediately' (implying synchronous, non-draft behavior) and mentions attachments via file paths, but lacks critical details: authentication requirements, error handling, rate limits, whether it's idempotent, or what happens on failure. For a mutation tool with zero annotation coverage, this is inadequate.

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 a single, efficient sentence that front-loads the core action. It wastes no words, though it could be more structured by explicitly listing key parameters or constraints. Every word earns its place, but it's slightly under-specified rather than concise.

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 complexity (a 6-parameter mutation tool with no annotations and no output schema), the description is incomplete. It lacks essential context: authentication needs, error handling, return values, and detailed parameter guidance. For a tool that sends emails—a critical operation with potential side effects—this is insufficient.

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 must compensate. It only mentions 'file path(s) as attachments', which partially explains the 'attachments' parameter. It ignores the other 5 parameters (account_id, to, subject, body, cc), leaving their purpose and format undocumented. The description adds minimal value beyond the bare schema.

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 the action ('send an email immediately') and specifies the resource (email) with a key feature (attachments). It distinguishes from siblings like create_email_draft (which creates drafts) and reply_to_email (which replies to existing emails), but doesn't explicitly mention how it differs from all email-related tools.

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 provides no guidance on when to use this tool versus alternatives like create_email_draft (for drafts) or reply_to_email (for replies). It mentions 'immediately' which implies urgency but doesn't specify prerequisites like authentication or account setup, nor does it indicate when not to use it.

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