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

Annotations already declare readOnly/idempotent/non-destructive, so the description's 'Read-only' is redundant. It earns credit instead for disclosing non-obvious behavior: newest-first ordering and the missing-vs-zero gap semantics for unopened months, which no annotation or schema conveys.

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?

Front-loaded with the core purpose and ordering, then progressively adds field semantics and units. Dense but nearly every clause carries information an agent needs; a minor trim is possible but nothing is padding.

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 no output schema, the description does the work of explaining return values: the meaning of actual (null when no data), base_target vs derived_target, the status enum values, and the units/ranges of fci, asset_past_useful_life_pct, asset_condition_avg, and risk_score_avg. Only pagination/return-shape details are left implicit.

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 baseline is 3, but the description adds real meaning beyond the schema by clarifying that the period range is compared against period_start and enumerating the filterable dimensions (system, building, network, metric, period).

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 ('List monthly technical Level of Service readings') and adds sorting order ('newest first') plus the unit of observation (one reading per tracked pair and metric per month). An agent can distinguish this from the singular get_los_status_snapshot without opening the 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?

Explains when readings exist ('recorded the first time anyone opens the Status screen... a month nobody opened it is missing rather than zero'), which is useful context for interpreting results. However, it never says when to prefer this over alternatives like get_los_status_snapshot or list_los_measurements, so usage is only implied.

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