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

Beyond the annotations, the description discloses meaningful behavior: client secret encryption (AES-256-GCM), no disk persistence, no echoing back, automatic propagation to odata_* and dmf_* tools, expiration, and the clear_connection lifecycle. These details are not present in the annotations and materially affect how an agent should treat credential state.

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 front-loaded with the core purpose, and every following sentence contributes non-obvious context: security guarantees, propagation behavior, recommendation, and locked-deployment exception. There is no filler or repetition of schema content.

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?

For a session-level connection setter, the description covers what the tool does, how the secret is handled, how long the connection lasts, how it is cleared, and when it must not be invoked. With the schema fully documenting parameters, no critical call-time information is missing even without an output schema.

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 100%, so the schema already documents all five parameters (baseUrl, tenantId, clientId, clientSecret, ttlMinutes). The description adds only high-level context ('URL + Entra app-registration credentials') rather than new per-parameter semantics, matching the baseline for complete schema coverage.

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 uses a specific verb ('register') and identifies the exact resource ('D365 F&O connection') with a clear session scope. It also distinguishes itself from sibling connection tools by naming d365fo_clear_connection and the odata_*/dmf_* consumers.

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 explicitly says 'Use this instead of resending the secret on every call,' giving a concrete when-to-use recommendation. It also covers the key exclusion: in locked server deployments (D365FO_LOCK_SERVER_CONFIG=true) the tool is disabled and server credentials are used instead, steering agents away from a broken call.

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