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

With no annotations, the description carries the full behavioral burden. It usefully discloses that output is a time series bounded 0-100, but says nothing about data source, latency, rate limits, how the response is shaped, or what happens when start_date/end_date fall outside available history.

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?

A single well-formed sentence with the verb and resource front-loaded and no filler. It is appropriately sized, though it passes over the opportunity to add a routing clause at little cost.

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 an 8-parameter indicator tool with no annotations and no output schema, the description covers purpose and value range but not the output structure, interval/period interaction, or edge-case behavior. Adequate to invoke correctly given a fully documented schema, but thin on the behavioral side.

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 all eight parameters (symbol, interval, series_type, time_period, date filters, max_data_points) are already documented in the schema. The description adds no parameter-level detail such as valid interval values or how time_period interacts with max_data_points, so the 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?

States a specific verb ('Fetch') plus a precise resource (RSI time series) and even bounds the value domain (0-100). It is clear what the tool returns, but it does not distinguish itself from sibling oscillators/indicators such as fetch_macd, fetch_sma, or fetch_ema, so an agent can't tell from the description alone which indicator tool to pick.

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?

There is no guidance on when to choose RSI over the closely related fetch_macd, fetch_sma, or fetch_ema tools, nor any prerequisite or exclusion note. The only implied usage is 'you want RSI', which the tool name already conveys.

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