get_sio

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

readOnlyHint=true already covers the safety profile, so the bar is lower, and the description clears it by disclosing that this wraps NBAPI GetSio and resolves a MERCURYKEY-vs-SIOKEY naming conflict in the underlying guide. That is real invocation-relevant context beyond the annotations, though it says nothing about response shape or error behavior.

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 sentence and the total length is short. The follow-up "Note:" sentence about the guide's worked example versus its Calling Parameters list is somewhat inside-baseball, but it earns its place by preempting a plausible MERCURYKEY/SIOKEY mistake.

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 single-param, read-only lookup with no output schema, the description covers purpose, the input key, and the naming caveat. It stops short of characterizing what "details" are returned, which is the only remaining gap for an agent deciding whether this tool gives it the fields it needs.

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 param already documents itself as required with a discovery pointer, so the baseline is 3. The description goes further by explaining why SIOKEY (not MERCURYKEY) is the value actually transmitted, which is meaningfully beyond what the schema alone conveys.

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 ("Returns the details of a single SIO") plus the identifying input ("for a given SIOKEY"). The singular "single SIO" implicitly contrasts with the sibling get_sios, so an agent can route between them without opening either 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 singular-vs-plural framing implies this is the detail-lookup counterpart to get_sios, and the schema's own param text points to get_sios for key discovery. However, the description itself states no explicit when-to-use or when-not-to-use condition, leaving routing to inference.

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