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

Annotations only declare a safe read; the description goes well beyond by disclosing the returned field set (name, datasource, non-secret credentials, connectionTest timestamps and message, sshAuthorizedKeysLine), the redaction guarantee ('Passwords, private and secret keys, and tokens never come back'), and the authorization scope ('Any member of the organisation can read it'). That is exactly the context annotations cannot carry.

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?

One dense paragraph, front-loaded with the purpose, then fields, then alternatives. The mid-sentence field enumeration is heavy but every element (secret redaction, SSH bastion case, failure message, auth scope) earns its place; a light restructuring into sentences would read better.

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?

There is no output schema, so the description must describe the return shape, and it does so field by field, including the conditional SSH field and the test-status subfields. With permissions, redaction and not-found behaviour all covered, nothing an agent needs before calling is missing.

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% and the single connectionId parameter is already documented in the schema as coming from fastero_list_connections. The description adds only the behavioural consequence of an unknown id, not new syntax or format semantics, so 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?

Opens with a specific verb and resource ('Read one data connection's settings') and immediately enumerates what those settings are. It explicitly distinguishes itself from fastero_list_connections (id + list, no details) and fastero_list_connection_schemas (tables), so an agent can route between the three 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?

'Use it to see where a connection points or why it fails' states the selecting condition, and both alternative siblings are named with what they return instead. It even names the substitute result for a bad id ('Connection not found'), removing ambiguity about failure semantics.

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