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

Annotations already declare the full safety profile (readOnlyHint, idempotentHint, destructiveHint=false, openWorldHint=false), so the description need not re-explain safety. It does add behavioral value by disclosing the exact payload: active state, team's recommended solution, last 10 chat messages, and case page link. With an output schema present, this is useful but not essential context, so a 3 fits.

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?

It is a single front-loaded sentence with no redundant preamble. The clause structure is slightly dense but each element earns its place by naming a distinct returned field.

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 read-only lookup tool with a complete annotation safety profile and a return schema, the definition is essentially complete: it names the input selector and summarizes the key return fields. Only the absence of explicit sibling routing keeps it from a 5.

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 both case_code (with pattern and example) and lang (with enum and default). The description only restates that lookup is 'by its case code' and adds no format or syntax detail beyond the schema. Baseline 3 is appropriate.

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 opens with a specific verb and resource: 'Returns the status of an SOS Flights case by its case code.' It clearly enumerates what status encompasses (active state, recommended solution, last 10 chat messages, case page link). It does not explicitly distinguish itself from siblings like sos_open_case or sos_prepare_case, so it stops short of a 5.

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?

Usage is implied rather than stated: the tool looks up an existing case by case code. There is no explicit when-to-use, no when-not, and no routing to alternatives such as sos_open_case for creating a case or sos_find_alternatives. The agent can infer the context but gets no direct guidance.

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