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

Annotations already declare a write-capable, destructive, idempotent, open-world operation, so the bar is lower. The description adds real behavioral detail: the conditional return (connected status plus listed tools and their read-only flags, or a sign-in link for the owner) and that a second address replaces the existing connection. It does not spell out the destructive impact of replacement, but stays consistent 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?

The content is all relevant, but it is delivered as a run of short, choppy clauses and the key framing ('for an app that shows data from another service') is stranded at the end. Some phrasing ('the name people know it by') is redundant with the schema.

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?

With a full output schema, 100% parameter coverage, and annotations, the description's job is narrow, and it fills it: connection state, the two possible return shapes, and replacement behavior are all covered. Permission/auth prerequisites for the write are the only notable omission.

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 100%, so the schema already documents url, label, and app_id. The description reframes url as 'the source's https MCP address' and label as 'the name people know it by', which mirrors the schema wording rather than adding new syntax or constraints; baseline 3 applies.

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+resource: it attaches a source to an app, identified by MCP url and label. The closing line 'For an app that shows data from another service' adds domain context. It never names a sibling tool, so an agent must infer differentiation from siblings like get_access or list_apps.

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 notes the tool 'works on an app with no data yet' and implies use when an app needs to read an external service, but there is no explicit when-to-use/when-not and no reference to alternative tools for connecting or configuring access.

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